Abstract

Decadal-scale observations of marine reserves suggest that indirecteffects on taxa that occur through cascading trophic interactionstake longer to develop than direct effects on target species.Combining and analyzing a unique set of long-term time series ofecologic data in and out of fisheries closures from disparateregions, we found that the time to initial detection of direct effectson target species (±SE) was 5.13 ± 1.9 years, whereas initial detectionof indirect effects on other taxa, which were often trait mediated,took significantly longer (13.1 ± 2.0 years). Most targetspecies showed initial direct effects, but their trajectories over timewere highly variable. Many target species continued to increase,some leveled off, and others decreased. Decreases were due tonatural fluctuations, fishing impacts from outside reserves, or indirecteffects from target species at higher trophic levels. The averageduration of stable periods for direct effects was 6.2 ± 1.2 years,even in studies of more than 15 years. For indirect effects, stableperiods averaged 9.1 ± 1.6 years, although this was not significantlydifferent from direct effects. Populations of directly targetedspecies were more stable in reserves than in fished areas, suggestingincreased ecologic resilience. This is an important benefit ofmarine reserves with respect to their function as a tool for conservationand restoration.